Astronomers using the Subaru Telescope in Japan have discovered a novel satellite of the Milky Way that they think is the shadowy companion ever discovered .
The galaxy , called Virgo I , join rough 50 know companions to our wandflower . It is locate 280,000 tripping - class away and is 124 light - years in diam – tiny even for a dwarf beetleweed . For compare , the milklike Way is about 100,000 light - twelvemonth across .
The galaxy was only recently discovered because it was below the detection limit of former survey . Looking at it in the sky , it appears 1.5 billion times fainter than the big Magellanic Cloud , our coltsfoot ’s biggest fellow , and it ’s even dimmer than most star . The galaxy has an absolute order of magnitude of -0.8 , making it 1.6 times fainter than our Sun , which is quite average .
Reported in theAstrophysical Journal , this find involve that Virgo I might be the first of many ultra - faint dwarf companions .
“ This find incriminate hundreds of light-headed dwarf satellites look to be discovered in the anchor ring of the Milky Way , ” elderly generator Masashi Chiba , from Tohoku University , said in astatement . “ How many satellite are indeed there and what properties they have , will give us an significant hint of understanding how the Milky Way form and how sinister subject contributed to it . "
Location ( go away ) and a denseness graph ( rightfulness ) of newly discovered coltsfoot Virgo I. Tohoku University / National Astronomical Observation of Japan
The structure in the universe are believed to form in a bottom - up manner , imply that the big clobber get this big by accumulating lots of little things . Large galaxies , like the Milky Way , are lie with to cannibalize their minuscule companions , steal their gas and stars . The front of a large population of small galaxies can solve some of the issues with our current understanding of the cosmos .
The “ dwarf galaxy problem ” is one of these issue . Simulations advise that there should be more little galaxies than what we have observed , and maybe the solution is that our instruments are only fetch good enough and we have but miss many of the object out there .
Virgo I was ascertain in the early datum press release of the Subaru Strategic Survey . The data represent about only 0.3 percent of the whole sky , so there could be many more diminutive galaxy out there .
